This invention relates to an apparatus for the treatment of tree diseases by chemical injection. More particularly this invention relates to an improved chemical applicator nozzle and a method of employing same.
Most tree diseases are caused by living organisms or pathogens, and it has been found that many of these can be combatted by applying appropriate chemicals to affected areas of the tree. In the treatment of Dutch elm disease, for example, it has been found advantageous to inject the chemical into the sapwood portion of the elm tree trunk.
In order to treat a tree by the chemical injection method, a hole is first drilled in the tree trunk and an applicator head is inserted therein. Pressurized chemicals are then injected into the tree via an appropriate pipe fitting or connection between the applicator head and the pressure line.
A typical prior art treatment head or applicator comprised a tubular shank portion having a threaded tip structure of a slightly larger diameter for positive engagement with the tree, and a socket attached thereto for insertion of the nozzle. Additionally, a sealing ring is sometimes included. Output orifices provided at predetermined locations in the nozzle shank portion would emit the desired chemicals in response to the application of same to a threaded aperture in the socket head which communicated therewith.
Successful installation of the aforementioned prior art nozzle necessitated the drilling of a first hole into the sapwood of the tree. The diameter of this hole would be slightly smaller than the outer diameter of the threaded nozzle tip. A second hole or counterbore having a diameter substantially equal to the nozzle head or sealing ring (if provided) would then be added to insure that when the output orifices in the nozzle shank reached the sapwood, the nozzle would be sealed. The counterbore facilitated sealing by enabling a sealing ring of the inwardly directed nozzle head surface portion to firmly seat against the wood. Following the drilling operation, the hole would be cleaned out in order to insure that the nozzle output orifices could reach the sapwood and that the nozzle head would be adequately sealed without interference from loose wood particles. In many instances, it was necessary to hammer the treatment head into the hole to insure a proper fit for the pressurized injection process thereby often damaging the treatment head, as well as being a time consuming task.
It is a fundamental object of the subject invention to provide an applicator nozzle for the injection treatment of trees which may be quickly and reliably utilized without the aforementioned installation complexities. Accordingly, the subject nozzle comprises a socket and an integral tapered shank portion having output orifices at its tip. The taper of the shank, together with exterior threads provided thereon, facilitate self tapping and self sealing of the nozzle. Furthermore, no hole cleaning operation is necessary, as the threads of the nozzle shank, rather than the inwardly directed surface of the nozzle head or separate sealing ring, provides sealing. The necessity of a second drilling operation (counterbore) and hammering step has thus been avoided.
It is a further object of this invention to provide a highly efficient and simplified method for the injection treatment of trees. In operation, a single hole is drilled and the aforementioned nozzle is inserted therein. The nozzle is threadably rotated until the output orifices at the shank portion tip have advanced to the sapwood area of the tree. Pressurized chemicals, applied via a threaded aperture in the nozzle head, are dispersed within the sapwood through the output orifices. A leakproof seal is formed between the shank threads and the wood in response to threaded advancement of the nozzle because of the taper of the shank. The prior art steps of counterboring and cleaning the nozzle insertion hole have thus been avoided. Furthermore, the penetration of the sapwood area by the nozzle shank has been reduced to a simple step.
It is another object of this invention to provide an integrally constructed applicator of extreme strength which is highly resistant to breakage. Prior art nozzles are often welded together from combinations of smaller parts. Often the smaller shank portion breaks in response to shear or stress. In the subject invention however, the shank portion is integral with the socket, and the device may be machined from a single casting or section of metal stock. Since the shank is tapered, its strength is greater than prior art nozzles having a uniform but smaller shank diameter. Furthermore, since the output orifices are located in the shank tip, a region not ordinarily subjected to stress, their presence does not significantly weaken the shank.
Another object of this invention is to provide an applicator treatment head which will threadably engage the outer wood areas of the tree into which the nozzle is inserted for added strength. The tapered threaded shank of the subject nozzle facilitates this, unlike prior art devices which theadably engage the weaker sapwood via the threaded tip portion of the nozzle shank. Accordingly, less likelihood of "stripping" is realized from the disclosed construction, and a firmer connection results.
It is yet another object of this invention to provide a method of chemically injecting trees and apparatus for use therewith that will minimize the damage incurred by the treated tree as well as to the treatment head itself. As previously mentioned, only one hole need be drilled, as the necessity for counterboring has been avoided. Since sealing is facilitated by the tapered shank threads, rather than a larger diameter socket head or sealing ring, adverse effect on bark, woodpulp, and applicator are minimized along with the time required for a normal installation. Further, there is no longer any need to pound or hammer the head into place. All factors considered, the unique applicator and method have significantly reduced the time for treating diseased trees.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.